In this issue of the Cleveland Clinic Journal of Medicine,1 Dr. Steven L. Cohn provides a succinct review of the recently published guidelines by the American College of Cardiology and American Heart Association (ACC/AHA) on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery.2 Although no drastic changes have been made in these guidelines, several significant modifications have been implemented and are highlighted in his review.

First, I am pleased Dr. Cohn described how the writing committee of the new guidelines handled the well-publicized breaches of scientific integrity by Dr. Don Poldermans, a prolific perioperative-medicine researcher at Erasmus University in the Netherlands who has contributed an abundance of literature that influenced clinical practice. Although some of his key publications were excluded by the ACC/AHA committee in its overall analysis, it remains unclear to me if simply ignoring some of his work is truly possible. For better or for worse, his publications have significantly shaped clinical practice in addition to guiding subsequent research in this field.

ASSESSING RISK

Along with continuing to endorse the Revised Cardiac Risk Index (RCRI),3 the guidelines now include another option for objective preoperative cardiovascular risk assessment. Dr. Cohn nicely outlines the pros and cons of the surgical risk calculator (often referred to as the “Gupta calculator”) derived from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database.4

Although the RCRI is not perfect, I agree with Dr. Cohn that the ACS NSQIP tool has limitations, including a cumbersome calculation (requiring a smartphone application or online calculator), lack of external validation, and use of the American Society of Anesthesiologists Physical Status Classification System, which has been notoriously confusing for generalists and has demonstrated poor inter-rater reliability among anesthesiologists.5,6

A patient may have very different risk-prediction scores depending on which tool is used

Of note, a patient may have very different risk-prediction scores depending on which tool is used. For example, a 66-year-old man with a history of ischemic heart disease, diabetes on insulin therapy, hypertension, and chronic kidney disease with a serum creatinine level greater than 2.0 mg/dL who is scheduled to undergo total hip arthroplasty would have a risk of a perioperative cardiovascular event of about 10% according to the RCRI, but only 1.1% according to the ACS NSQIP calculator. How widely this newer risk-stratification tool will be adopted in clinical practice will be interesting to observe.

In what appears to be an effort to simplify the guidelines, the ACC/AHA now recommends combining the patient’s clinical and surgical risks into estimating an overall perioperative risk for developing major adverse cardiac events. This estimate is now whittled down to only two categories: “low risk” and “elevated risk.” I am concerned that the new guidelines may have become too streamlined and lack the direction to assist providers in making important clinical decisions. Most notably, and as Dr. Cohn appropriately suggests, many patients will be in a gray zone with respect to whether cardiac stress testing should be obtained before surgery.